This invention relates to a stacker device for packages of a plurality of identical plastic or paper containers supported in a tray or shipping carton for the purpose of providing compressive load-bearing capability to the package. Although not limited thereto, the invention is especially adapted to shrink wrapped packages of a plurality of plastic or paper containers supported in a tray and surrounded by a plastic wrap.
For many goods the packing of multiple containers in a relatively shallow base tray surrounded by a transparent shrinkable plastic wrap, instead of a conventional corrugated cardboard carton, has become commonplace. With the increasing popularity of warehouse-type grocery stores and supermarkets, such packages offer convenience in that upon removal of the plastic wrap, the entire package may be shelved or stacked for display purposes. Where the goods themselves have considerable load-bearing strength, such as canned goods and glass bottled goods, such shrink wrapped packages can readily be stacked. More recently, it has become commonplace to package many goods in lighter weight synthetic resinous plastic containers such as bottles, jugs, and the like. Other goods are packed in paper containers offering little or no load-bearing strength.
Shrink wrapped packages of such lighter weight plastic or paper containers are easier to handle, are cheaper to ship, etc. However, they lack significant compressive load-bearing strength so that, if, stacked too high, one or more of the containers in the lowermost package may rupture. Whether the contained goods are beverages or table syrups or motor oils or cooking oils, an undesirable mess is created which may ruin not only the goods in the package including the ruptured container, but adjacent packages as well. Frangible goods, such as chips and flakes and the like, which are often sold in paper containers, may be rendered unsaleable if crushed. The present invention is directed to the alleviation of these problems. THE PRIOR ART
Prior attempts to increase the load-bearing capacity of packages of varying kinds are exemplified by the following U.S. Patents:
______________________________________ Kim 3,327,919 June 27, 1967 Sargent et al 3,595,384 July 27, 1971 Roth 3,826,357 July 30, 1974 Meighan 4,062,448 December 13, 1977 Schwaner 4,251,020 February 17, 1981 ______________________________________